See also:

Engine Power Messages
ENGINE POWER IS REDUCED This message displays when the vehicle's engine power is reduced. Reduced engine power can affect the vehicle's ability to accelerate. If this message is on, but there ...

What to Use
To determine what kind of fluid to use, see Recommended Fluids and Lubricants  . Always use the proper fluid. Notice: Use of the incorrect fluid may damage the vehicle and the damages may not ...

Diagnostics
OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if the v ...